Critical Resource Required for Life Air Minerals Energy
Slide 5
Water H 2 O Molecule Covalent Bonds Hydrogen Bonds
Slide 6
Physical Properties Unusually high boiling point Expands when
frozen High specific heat
Slide 7
Biological Properties Great solvent Transport media Support
media
Slide 8
Critical Resource Quantity: for a growing population All Earths
water in a gallon jar Available fresh water = one tablespoon Other
fresh water = two tablespoons Quality: given use and misuse
Slide 9
Water for People Lakes (FlorenceClear Lake) Rivers (Grants
PassRogue River) Groundwater (Rural OregonWells)
Slide 10
Large Urban Areas San Francisco YosemiteHetch Hechy Reservoir
Portland Bullrun Watershed Wells along the Willamette Medford
Little Butte Creek Rogue River
Slide 11
Agriculture 40% US water to agriculture 5% of US farmland is
irrigated These produce 20% of farm products 1 Gallon milk = 4
Gallons water 1 Tomato = 8 Gallons water
Slide 12
Electric Power More water used here than any other use 4,000
Gallons = 1 kilowatt 10 - 100 W light for 1 hour 90% =
Thermoelectric = 131 X 10 9 Gal/day 10% = Hydroelectric
Slide 13
Industry 36 X 10 9 Gal/day Paper, petroleum, chemicals, metals
Commercial (military, college, office, restaurant)
Slide 14
Domestic Use Toilets, showers, lawns, washing clothes Toilet
3.5 to 7 Gal/flush (low-flow = 1.6 gal)
Slide 15
Environmental Use Stream flow minima Wildlife habitat
Recreation
Slide 16
Conservation One penny = 160 eight-ounce glasses Why
conserve?
Slide 17
Source(s) of Water Only one source.Earth.Ocean Fresh water.Sun
Land watersheds streams Rivers lakes reservoirs ocean
Slide 18
A particular area of concern for many people is groundwater
contamination. Groundwater is usually defined as water that lies
below the surface of the land. For practical purposes, though,
groundwater is usually thought of as water underground that can be
removed by wells. Those sources of ground water are referred to as
aquifers. When an aquifer becomes contaminated, that contamination
can affect a wide area and take years to clean up. Some common
sources of groundwater contamination include improper disposal of
wastes, faulty septic tanks, landfills, pesticides and
fertilizers.
Slide 19
Slide 20
Types of Groundwater Contamination Groundwater pollution caused
by human activities usually falls into one of two categories:
point-source pollution and nonpoint-source pollution. Point-source
pollution refers to contamination originating from a single tank,
disposal site, or facility. Industrial waste disposal sites,
accidental spills, leaking gasoline storage tanks, and dumps or
landfills are examples of point sources.
Slide 21
Chemicals used in agriculture, such as fertilizers, pesticides,
and herbicides are examples of nonpoint- source pollution because
they are spread out across wide areas. Similarly, runoff from urban
areas is a nonpoint source of pollution.
Slide 22
Slide 23
Natural Substances Some groundwater pollution occurs naturally.
The toxic metal arsenic, for instance, is commonly found in the
sediments or rock of the western United States, and can be present
in groundwater at concentrations that exceed safe levels for
drinking water. Radon gas is a radioactive product of the decay of
naturally occurring uranium in the Earth's crust. Groundwater
entering a house through a home water- supply system might release
radon indoors where it could be breathed.
Slide 24
Petroleum-based Fuels One of the best known classes of
groundwater contaminants includes petroleum-based fuels such as
gasoline and diesel. Nationally, the U.S. Environmental Protection
Agency (EPA) has recorded that there have been over 400,000
confirmed releases of petroleum- based fuels from leaking
underground storage tanks.
Slide 25
Slide 26
Gasoline consists of a mixture of various hydrocarbons
(chemicals made up of carbon and hydrogen atoms) that evaporate
easily, dissolve to some extent in water, and often are toxic.
Benzene, a common component of gasoline, is considered to cause
cancer in humans, whereas other gasoline components, such as
toluene, ethylbenzene, and xylene, are not believed to cause cancer
in humans but may be toxic in other ways.
Slide 27
Chlorinated Solvents Another common class of groundwater
contaminants includes chemicals known as chlorinated solvents. One
example of a chlorinated solvent is dry-cleaning fluid, also known
as perchloroethylene. These chemicals are similar to petroleum
hydrocarbons in that they are made up of carbon and hydrogen atoms,
but the molecules also have chlorine atoms in their structure.
Slide 28
The International Agency for Research on Cancer has classified
tetrachloroethene as a Group 2A carcinogen, which means that it is
probably carcinogenic to humans. Like many chlorinated
hydrocarbons, tetrachloroethene is a central nervous system
depressant and can enter the body through respiratory or dermal
exposure. Tetrachloroethene dissolve fats from the skin,
potentially resulting in skin irritation.
Slide 29
Tetrachloroethene is a common soil contaminant. Because of the
mobility of PCE in groundwater, its toxicity at low levels, and its
density (which causes it to sink below the water table), cleanup
activities are more difficult than for oil spills. Recent research
has focused on the in place remediation of soil and ground water
pollution by tetrachloroethylene. Instead of excavation or
extraction for above-ground treatment or disposal,
tetrachloroethylene contamination has been successfully remediated
by chemical treatment or bioremediation. Bioremediation has been
successful under anaerobic conditions by reductive dechlorination
by Dehalococcoides sp. and under aerobic conditions by cometabolism
by Pseudomonas sp.
Slide 30
MTBE: GASOLINE ADDITIVE Methyl tert -butyl ether (MTBE) is used
almost exclusively as a gasoline additive to help reduce harmful
tailpipe emissions from motor vehicles. MTBE has been credited with
improving air quality by significantly reducing carbon monoxide and
ozone levels in areas where the additive has been used. But
Slide 31
There is widespread concern about MTBE in drinking- water
sources because of potential human-health effects and its offensive
taste and odor. The U.S. Environmental Protection Agency has
tentatively classified MTBE as a possible human carcinogen, but has
not yet established a drinking- water regulation. The agency,
however, has issued a drinking-water advisory of 20 to 40
micrograms per liter (20 to 40 parts per billion) on the basis of
taste and odor thresholds.
Slide 32
1 Maximum Contaminant Level Goal (MCLG) - The maximum level of
a contaminant in drinking water at which no known or anticipated
adverse effect on the health effect of persons would occur, and
which allows for an adequate margin of safety. MCLGs are non-
enforceable public health goals. 2 Maximum Contaminant Level (MCL)
- The maximum permissible level of a contaminant in water which is
delivered to any user of a public water system. MCLs are
enforceable standards. The margins of safety in MCLGs ensure that
exceeding the MCL slightly does not pose significant risk to public
health.
Slide 33
Contaminates A milligram per liter of water is equivalent to 1
ppm (part-per-million) because a liter of water weighs 1000 grams
and a milligram is 1 one thousandth of a gram. The various forms of
nitrogen and phosphorus most available to plants (nitrate-N,
ammonium-N and phosphate-P) are typically present at concentrations
or levels of only 0.001 to 0.500 mg/L. These are typically
expressed as micrograms-per-liter or ug/L. A microgram /L is 1 one
thousandth of a milligram/L. It is also equivalent to 1 ppb
(part-per-billion).
Slide 34
Toxic pollutants such as heavy metals like cadmium and mercury
usually exist at sub - ppb levels and can be considered to be a
problem at ppb levels. Some organic contaminants, a diverse group
of chemicals that includes pesticides, PCBs and dioxins, may be
measured at sub- ppb levels and may be expressed as ng/L
(nanograms-per-liter = parts-per- trillion) or even 1 pg/L
(picograms- per-liter = parts-per-quadrillion).
Slide 35
These are all very dilute concentrations and below are listed
some comparisons to provide some intuitive feel for how low these
levels are. By the way, seawater has a salt content of about 32 g/L
(32 parts-per-thousand which is the same as 3.2 % since 1 percent =
1 part-per-hundred). This is also equivalent to 32,000 ppm
(part-per-million).
Slide 36
Concentrations One-Part-Per-Million one automobile in
bumper-to-bumper traffic from Cleveland to San Francisco one inch
in 16 miles one minute in two years one ounce in 32 tons one cent
in $10,000
Slide 37
One-Part-Per-Billion one 4-inch hamburger in a chain of
hamburgers circling the earth at the equator 2.5 times one silver
dollar in a roll of silver dollars stretching from Detroit to Salt
Lake City one kernel of corn in a 45-foot high, 16-foot diameter
silo one sheet in a roll of toilet paper stretching from New York
to London one second of time in 32 years
Slide 38
One-Part-Per-Trillion one square foot of floor tile on a
kitchen floor the size of Indiana one drop of detergent in enough
dishwater to fill a string of railroad tank cars ten miles long one
square inch in 250 square miles one mile on a 2-month journey at
the speed of light
Slide 39
One Part Per Quadrillion one postage stamp on a letter the size
of California and Oregon one human hair out of all the hair on all
the heads of all the people in the world one mile on a journey of
170 light years